Injection device for internal combustion engines



July 19,1938. L. H. L. BELLEM' 2,124,133 INJECTION DEVICE FOR INTERNALCOMBUSTION ENGINES Filed Sept. 14, 1936 3 Sheets-Sheet l on al u l (MMI'IIIIIII July 19, 1938.- L. H. L, BELLI-:M

INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Sept. 14, 1956 3Sheets-Sheet 2 July 19,y 1938. 2,124,133

INJECTION DEVICE FOR INTERNAL coMBUsTIoN ENGINES 1 l.. H. l.; BELLEM 3Sheelts-Sheet 3 Filed Sept. 14, 1956 wnr mais 656176772/ Patented July19V, 1938 INJECTION DEVICE FOR INTERNAL M- BUSTION ENGINES Louis HenriLibert Bellem, Asnieres, France Application September 14, 1936, SerialNo. 100,797

' In Belgium January 7, 1936 The present invention relates toimprovements in injection devices for internal combustion engines.

In devices of this kind, the fuel is generally supplied by a pistonwhich is operated by a cam. The

speed of said piston and consequently the injection speed, i. e. thespeed at which the fuel is projected into the engine, is small at thebeginning and at the end of an injection stroke, which results in a poratomization.

In order to obviate such drawback, means have already been proposedwhereby the injection only starts after the beginning of the injectionstroke and stops before the end of same, so that l5 the Whole of theinjection is effected at full speed, therefore giving a goodatomization. In particular, it has been proposed to make the pumpcylinder movable, so that its open end is only connected to the apertureof the injection passage 20 during a given and adjustable portion of thepiston stroke. At the end of the injection said cylinder must thereforebe moved away from said` aperture, while the piston still continues tomove towards same, which fact sets a problem of me- 25 chanics.

The formerly proposed arrangement was devised for fuel pumps mountedoutside the engine,-

and one object of this invention is to use an arrang/ement of such kindin pumping injectors,

-30 that is, in injectors having their own means for forcing the fuelinto the cylinders on which said injectors are directly mounted.

Another object of the invention is to provide a novel and very compactarrangement. In this ar- 35 rangement, the pump piston carries a primarywedge which co-operates with a movable member, at a point of itsdownward stroke, to impart to same a transversal movement, and saidmember co-operates as a secondary wedge with the pump 40 cylinder toimpart to same, when being so moved, a small upward movement which liftssame from saidinjection passage aperture. In other words, the loweringof said piston causes, by means of a double wedge device, a lifting`of.said cylinder.

45 The downward stroke denotes here the delivery stroke towards theinjection passage aperture. The connection of said primary wedge to thepiston can be adjustable in order to allow the instant when the cylinderis lifted and when the injection 50 ends to be adjusted.

According to an embodiment'pf-the invention, said primary wedge isformed of a sleeve carried on the piston and the lower edge of which isbevelled to form a wedge, and the secondary 55 wedge is formed ofradiallyy guided balls co-op- (Cl. 2ML-107.2)

erating with a tapered ange on the cylinder. In order to reduce thefriction of the balls, one ball or a pair of balls can be insertedbetween each wedge forming ball and the guideway of same. Said sleevecan be lightly screwed on the piston 5 and be provided with spur gearteeth enabling it to be turned during operation for adjusting the end ofthe injection. In case of a multi-cylinder engine, the sleeves of thepumping injectors of all the cylinders can be controlled together, as bya 10 rack engaging said teeth.

A further object of the invention is to provide a simple control forpumping injectors mounted on an engine. In this control, the cam for theinjector rocker is formed on the exhaust valve rocker, which is in turncontrolled by an exhaust cam carried. on one of the conventional camshafts of the engine, and the contours of said `cams are' such that atthe injection time (which means the instant when the injection is to beeffected) the exhaust cam moves the exhaust valve rocker in order thatthe latter may move the injection rocker and cause an injection and thatit may come near the exhaust valve without opening said valve, while atthe subsequent exhaustion time, it further moves said exhaust camrocker, so that the same opens said valve without further moving saidinjection rocker.

Other features of the invention relate to the injection nozzle structurewith the adjacent passage. In order to avoid the reflux of the fuel,

a check valve (ball) is usually arranged in that passage. 'I'his ball issupported on a spring-returned plunger which is more or less depressedby the fuel pressure to let the fuel pass and which is then returnedupwardly by its spring to seat the ball. Usually, such plunger ishollow, provided with holes at the top and opening by its open lower endinto the nozzle, said spring being accommodated Within said plunger.Accord- 40 ing to the invention, said plunger can be solid and beengaged in the nozzle, spiral grooves being provided for the fuel andthe spring being arranged around said plunger.

Moreover, the end of said plunger can be extended by a taperedprojection engaged in the nozzle opening, so as to leave, between itselfand the edge of said opening, an annular gap which will be all the wideras the said plunger is further depressed. An injection cross-section isthus obtained, which is proportioned to the injected, quantity, sincetheplunger is -all the more depressed as the fuel is delivered ingreater quantity. Therefore, the injection speed only slightly varieswith the output, whereby by suitably proportionbest atomization at anyspeed of the engine.

Other features and pecularities of the invention will appear from thefollowing description with reference to the accompanying drawings, inwhich:

Fig. 1 is a longitudinal section of a pumping injector according to theinvention;

Fig. 2.shows the same in a longitudinal section taken at right angles toFig. 1 and in. a diierentposition;

Fig. 3 is a view similar to Fig. 1 but in still another position;

Fig. 4 is a plan view of the lower body of said injector;

Fig. 5 is a plan view of the whole injector;

Fig. 6 is an elevation of a control device for said injector;

Fig. '7 shows the same in plan view, partly in section;

Fig. 81s a partial longitudinal section of a detail modiiication;

Fig. 9 is a partial tangential section on the line IX-IX in Fig. 10;

Fig. 10 is a cross section on the line X--X in Fig. 8;

Fig. 11 is a partial longitudinal s ection of a structural modificationof the ,injection nozzle; and

Figs. l2 and 13 are partial longitudinal sections of another structuralmodification of the injection nozzle, in two different positions.

I is the body of a pumping injector which can be mounted in the place ofa known injector. Said body is lined with a guide sleeve 2 forming aninlet chamber and having two diametrically opposed grooves 3 and 4(Figs. 1 and 4) for the inlet and the outlet of the fuel which a feedpump of any type continually circulates. The fuel arrives through A,passes through the groove 3 and flows out through the spiral groove 4 toilnally reach the outlet S. In a multi-cylinder engine, the inlets andthe outlets of all the injectors are in parallel on the same inlet oroutlet manifold, respectively;

In the guide 2 slides a movable cylinder 6 in which works a piston Ibetween said cylinder and piston is interposed a spring 8 which is heldin compression in a box 9 (formed of two members).

Said box 8 is placed in a sleeve I0 adapted to slide in a hollow memberI I secured on the body I.. A push member |2 is secured to the box 9 bya circular groove in which the two half members of said box are tted.Said push member is to be operated by a rocker, 'a cam or any otheroperating member. It has a groove I2 in which ts the rocker (or otheroperating member) (not shown), which consequently prevents the pushmember from rotating. The sleeve III is screwed on said push member bymeans of a long pitched thread.

'I'he lower edge I3 of the sleeve I0 is bevelled and is adapted to actas a wedge on balls I5 which themselves act as a wedgel on a taperedflange I6 on the cylinder 6. At its upper part, said'sleeve has atoothing I 4 Iwhich enables it to be rotated by a rack 20 to vary theheight between the bearing point of the rocker arm.l and the edge I3.

'f 'Ihe bottom of the inlet chamber is formed of V[cylinder 6 can seaton said cone by its' open lower end and is then connected to theinjection passage.

Fig. 1 shows the pumping injector in the inoperative position andadjusted for its maximum output, i. e. with the edge I3 at its greatestdistance from the balls I5. In this position, whatever be the outputrequired, owing to aspring 8', there is no play between the rocker armand the push member I2, nor between the roller and the cam of the rocker(not shown). At this moment, there is play J of about 1 mm. between thecylinder 6 and the cone 2| Under the action of a rocker, a cam or of anyother control member, on the push member I2, the whole structureconnected to the latter moves downwards, but after a stroke J, thecylinder 5 stops on the cone 2| on which it is pressed by the spring 8,which is always compressed to about 10 kgs. The joint between thecylinder 6 and the cone 2| is quite tight. 'I'he injection begins atthis instant. The beginning of the injection is thus invariable, whichenhances operation when idling. v

The stroke continues, the spring 8 being further compressed (see Fig.2). When the bevel I8 engages the balls I5,'the latter, by movingradially on a washer I1, lift the cylinder 6 from its seat 2| (see Fig.3). The injection stops then at once, this being a necessary conditionfor a satisfactory atqmization.

The distance which remains between the edge I3 and the balls I5 when thecylinder 6 touches the cone 2| ydetermines the output. Said output cantherefore be adjusted by screwing or unscrewing the sleeve I0 on thepush member I2. This control is eiected by means of the rack 20 whichmaintain the leak between said cylinder and cone,

and the piston delivers into the feed circuit.

When the roller of therocker rolls down the cam, the springs 8 and 8co-operate to bring back the movable structure of the injector to theinoperative position. When the spring 8 has completely expanded Withinthe limits of the box 8, pressing the cylinder 6 and the piston Iagainst the ends oi' said box, the spring 8' continues to litt saidstructure to re-establish the play J. The filling of the pump is thencompleted, and another injection can take place.

A check valve is provided in the injection passage, being formed of aball 22. Said ball is supported on a hollow plunger 24, whichl is urgedupwards by a spring 23, placed` in the plunger, to press said ballagainst its seat in the cone 2|. As soon as the cylinder 6 leavesthecone 2|, said plunger, which is open at `the bottom and which has atthe top a hole substantially smaller than the top aperture of said cone,acts as a piston and rises to prevent any leakage at the injection holesin the nozzle 25.

A control mechanism i'orv the push members I2 of the pumping injectorsis shown in Figs. 6 and '7. Such mechanism can be readily mounted on anexisting engine in order to transform same into an engine with pumpinginjectors. It allows, the control of the pump injectors through one ofthe cam shafts which already exist on the engine, viz. through theexhaust cam shaft. It can be used for controlling pumping injectors ofany type.

In the example shown, the exhaust shaft 30 is used. At 3| is shown thecam which operates the exhaust valve, not shown but the spring 32whereof is shown in Fig. 6. The cam 3| operates a rocker 33, which isretracted by a spring 34 and acts on the stem 35 of said exhaust valve.

Said cam 3l usually has the contour shown in dotted lines in Fig. 6.With the contour according to the invention, shown in full lines, theextreme inoperative position of the rocker 33, to which it is urged bythe spring 34, is brought further back, so that said rocker is lifted adistance J above the stem 35 of the exhaust valve. The connectionbetween the new contour of the cam 3| and the former one forms a rise3|' which brings again said rocker into contact with said stem, whilethe usual projection or boss 3Ib, which begins at OE., further movessaid rocker, so that it opens said valve.

Provided on the exhaust rocker itself is a cam 36 intended to control arocker 31 which operexhaust valve.

ates the push member I2 of the pumping injector and which has a followerroller 38. It has been stated that the passage of the first rise 32aresults in a first movement of the exhaust rocker, during which theexhaust valve is not operated. Now, the cam 36 is such that'this rstmovement of the exhaust rocker operates the injection rocker to cause aninjection. Obviously, the rise 3|a is located on the cam 3| so that theinjection will be caused at the desired instant, i. e. the injectiontime. ,The cam 36 continues in a concentric portion 39 which no longermoves the injection rocker as the boss 3|b further moves the exhaustrocker to open the The .suction stroke of the push member I2 takes placeas the exhaust rocker, after having closed the exhaust valve, is liftedfrom the stem 35, which fact occurs during the passage of the firstportion of the new contour of the cam 3|, approximately between the'point F.E. and the rise 3I.

It will be noted that the new contour of the cam 3| is situated insidethe former one, so that an existing cam can be transformed by milling orother tooling operation into a cam according to the present invention.As is more particularly seen in Fig. 7, the cylinder head of the enginerequires no modification.

In view of this control, the inlet cam shaft also could be used, insteadof the exhaust cam shaft.

The wedge forming balls I5 of the device shown in Figs. l to 5 cannotsimply roll at the same time on Ithe bevel I3, the tapered flange I6 andthe washer I'I: a certain amount of sliding must take place, either atleast on the washer I1, or distributed on two of said surfaces or on thethree. The device shown in Figs. 8-10 allows'this total amount ofsliding to be reduced. In this device, a pair of balls I5' is insertedbetween each ball I5 and said washer I1, which is here relatively thickand is provided with suitable slots I'I to accommodate said balls. Anannular spring I5" presses the balls I5' outwards. This device allowseach ball I5 to rotate on itself in the opposite direction when rollingon the bevel I3, the tapered flange I6 and the balls I5.

In the modification shown in Fig. 11, the small hollow plunger 24 shownin Fig. 1 is replaced by a longer, solid plunger 24', engagingthe nozzle25 and provided with spiral grooves 24*i through which the fuel passesinto the injection opening 25". A better atomization-of the fuel is thusobtained.

Instead of ending the plunger 24' within the nozzle, before theinjection opening 25, it may be extended. according to the modicationshown in Figs. 12 and 13, by a taperedvprojection 26 engaging saidinjection opening. The object of such arrangement is as follows: owingto the arrangement of Figs. '1-5, the injection occurs during themovement at full speed of the push member I2, yet this speed isproportional to that of .the engine; during each injection, the fueloutput rate is therefore proportional tothe engine speed; and theinjection speed, which is equal to the quotient of said output rate bythe section of the injection opening, varies in the same proportion withan opening having a fixed section and gives a poor atomization at. lowengine speeds. Now, owing to the projection 26, theplunger 24', which isdepressed, at each injection, all the more `as the output rate of sameis increased, controls the annularsection of the injection opening inconformity with said output rate. Thus, a substantially constantinjection speed, and therefore a uniformly good atomization, can beobtained at any engine speed. In Fig. 12, the plunger 24 is in its upperposition, and the larger end of the projection 26 engages the opening25a and entirely closes the same; while in Fig. 13, said projection isnearly in its most depressed position.

It is obvious that the invention has only been described and illustratedherein in an explanatory and not limitative manner and thatmodifications can be made within the scope of the appendedA claims.

I claim: 1. Fuel injector for internal combustion engines', comprising ahollow member forming an vmember for depressing said cylinder to tightlyconnect its open end to said passage aperture during a section of theinjection stroke of said piston, and means in said hollow member forlifting said cylinder from said aperture at the end of said strokesection, whereby injection of fuel into theengine is caused to occuronly dur- .ing said stroke section.-

2. Fuel pump for internal combustion engines, comprising a hollow memberforming an inlet chamber with a substantially vertical cylindricalportion, and providing an injection passage having an aperture in saidchamber, below said cylindrical portion of same, check valve meansinsaid passage, a nozzle structure directly connected to said passageand opening into the engine,'a fuel pump cylinder slidably mounted insaid vertical cylindrical portion of said chamber and having an open'lower end, a piston adapted to work in said cylinder, means in saidhollow member for depressing said cylinder to tightly connect its openend to said passage aperture during a section of the injection stroke ofsaid piston, a primary. wedge connected to said piston for reciprocationtherewith, and a transversally movable member in said hollow member,adapted to be moved by said primary wedge at the end of said strokesection and when so moved, to lift said cylinder from said aperture,whereby injection of fuel into the engine is caused to occur only duringsaid stroke section.

3. Fuel pump for internal combustion engines, comprising a hollow memberforming anb inlet chamber with a substantially vertical cylindricalportion, and providing an injection passage having an aperture in saidchamber, below said cy' lindrical portion of same, check valve means insaid passage, a nozzle structure directly connected to said passage andopening into the engine, a fuel pump cylinder slidably mounted in saidvertical cylindrical portion of said chamber and having an open lowerend, a piston adapted to work in said cylinder, means in said hollowmember for depressing said cylinder to tightly connect its open end tosaid passage aperture during a section of the injection stroke of saidpiston, a primary wedge adjustably connected to said piston forreciprocation therewith, a transversally movable member in said hollowmember, adapted to be moved by said primary wedge at the end of saidstroke section and when so moved, to lift said cylinder from saidaperture, and means for adjusting the position of said wedge relativelyto said Apiston to adjust said stroke section end, whereby injection offuelinto the `engine is caused to occur only during said adjustablestroke section.

4. Fuel pump for internal combustion engines, comprising a hollow memberforming an inlet 'chamber with a substantially vertical cylindricalportion, and providing an injection passage having an aperture in saidchamber, below said cylindrical portion of same, check valve means insaid passage, a nozzle structure directly connected to said passage andopening into the engine, a fuel pump cylinder slidably mounted in saidvertical cylindrical portion of said chamber and having an open lowerend, a piston adapted to work in said cylinder, means in said hollowmember for depressing said cylinder to tightly connect its open end tosaid passage aperture during a section of the injection stroke of saidpiston, a sleeve on said piston, arranged around said cylinder andhaving an inner bevel on its lower end, radially movable balls in saidhollow member and adapted to be operated by said bevel at the end ofsaid stroke section, and a downwardly tapered flange on said cylinderand so co-operating with said balls that said cylinder is lifted'i'romsaid aperture as said balls are moved by said sleeve end bevel, wherebyinjection of fuel into the engine is caused to occur only during saidstroke section.

5. Fuel pump for internal combustion engines, comprising a. hollowmember forming an inlet chamber with a substantially verticalcylindrical portion, and providing an injection passage having anaperture in said chamber, below said cylindrical portion of same, checkvalve means in said passage, a nozzle structure directly connected tosaid passage and opening into the engine, a fuel pump cylinder slidablymounted in said vertical cylindrical portion of said chamber and havingan open lower end, a piston adapted to work in said cylinder, means invsaid hollow member for depressing saidcylinder to tightly connect itsopen end to said passage aperture during a section of the injectionstroke of said piston, a sleeve on said piston, arranged around saidcylinder and having an inner bevel on its lower end, radially movableballs in said hollow member and adapted to be operated by said bevel atthe end of said stroke section, radial guideways for said balls, otherballs between said guideways and the first said balls and a downwardlytapered flange on said cylinder and so co-operating with the flrst saidballs that said cylinder is lifted from said aperture as said balls aremoved by said sleeve end bevel, whereby injection of fuel into theengine is caused to occur only during said stroke section.

6. Fuel pump for internal combustion engines, comprising a hollow memberforming an inlet chamber with a substantially vertical cylindricalportion, and providing an injection passage having an aperture in saidchamber, below said cylindrical portion of same, check valve means insaid passage, a nozzle structure directly connected to said passage andopening into the engine, a fuel pump cylinder slidably mounted in saidvertical cylindrical portion of said chamber and having an open lowerend, a piston adapted to work in said cylinder, means in said hollowmember for depressing said cylinder totightly connect its open end tosaid passage aperture during a section of the injection stroke of saidpiston, a sleeve movably screwed on said piston, arranged around saidcylinder and having spur gear teeth on' its upper end and an inner bevelon its lower end, a toothed control member adapted to engage said sleeveend teeth throughout the reciprocations of said sleeve and to be movedfor adjusting said sleeve on said piston, radially movable balls in saidhollow member and adapted to be operated by said sleeve end bevel at theend of said piston stroke section, and a downwardly tapered flange onsaid cylinder and so co-operating with said balls that said cylinder islifted from said aperture as said balls are moved by said sleeve endbevel, whereby injection of fuel into the engine is caused to occur onlyduring said stroke section.

7. Fuel injector for internal combustion engines, comprising a hollowmember forming an inlet chamber with a substantially verticalcylindrical portion, and providing an injection passage having anaperture in said chamber, a nozzle structure directly connected to saidpassage and opening into theengine, said structure including a nozzleproper, a check valve in said passage, a solid plunger behind said checkvalve, engaged in said nozzle and adapted to be depressed through sameby the fuel input, and a spring arranged around said plunger and urgingsame to close said valve, said plunger having spiral grooves to let thefuel from said passage into said nozzle, a fuelpump cylinder slidablymounted in said vertical cylindrical portion of said chamber and havingan open lower end, a piston adapted to work in said cylinder, means insaid hollow member for depressing said cylinder to tightly connect itsopen end to said passage aperture during a section of the injectionstroke of said piston, and means in said hollow member for lifting saidcylinder from said aperture at the end of said stroke section.

v8. Fuel injector for internal combustion engines, comprising a hollowmember forming an inlet chamber with a substantially verticalcylindrical portion, and providing an injection passage having anaperture in said chamber, a nozzle structure directly connected to saidpassage and having an injection opening which opens into the engine,said structure including a nozzle proper, a check valve in said`passage, a solid plunger behind said check valve, engaged in said calportion of said chamber and having an open lower end, a piston adaptedto work in said cylinder, means in said hollow member for depressingsaid cylinder to tightly connect its open end to said passage apertureduring a section of the injection stroke of said piston, and means insaid hollow member for lifting said cylinder from said aperture at theend of said stroke section.

LOUIS HENRI LIBERT BELLEM.

